Gauge



Patented Nov. 14, 1922.

UNITED STATES PATENT OFFICE.

i ROBERT F. RUNGE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNORTO THE HESS.

BRIGHT MANUFACTURING COMPANY, A CORPORATION OF DELAWARE.

GAUGE.

Application led April 3, 1920. Serial No. 370,975.

To a?! whomt may concern.'

Be it known that I, Ronnirr F. RUNGE, a citizen of the United States, residing at Philadelphia. in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Gauges. of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to adjustable or reformable gauges of the plug gauge type, and has for an object to provide a gauge of this character which, when the measuring surface or periphery becomes worn, can be radially restored to its former condition and size, and also one in which the radius of the cylindrical segments may be either increased or decreased as occasion demands.

In the drawings accompanying this specication one practicable embodiment of the invention is illustrated.` which ,drawingsa Figure l shows a forni of plug gauge equipped with my improvement and whereln there is shown,'at one end of the instrument, maximum and minimum plugs.

Fig. 2 is an enlarged cross section taken at about the plane of line 2-2 of Fig. 1, and

Fig. 3 is a. diagram illustrating the manner or method of adjusting the gauge.

In Fig. l. a form'of gauge is illustrated wherein there is provided a handle 7, preferably knurled, which car-ries a plug for measuring oi' testing the inside surfa or bore of some body. The gauge hei-ein illustrated is of a type for measuring the c vlindrical bores of various work pieces and may therefore be described as a. cylindrical plug gauge. The particular form shown is made up as a tolerance gauge. there being a minimum or fro )ortion 8 and a maximum or no go portion 9. Heretofore in plug gauges, and particularly cylindrical plug gauges, it has been found that there has been waste owing to the difficulty of expanding the measuring surfaces of the plug. after these have been worn in use, so as to bring them to the prescribed diameter. According to my invention the measuring surface or work engaging surface 10 is shown divided into segments. thatis if the plug is cylindrical these are the segment of aA cylinder. There are preferably two of these measuring portions having the proper segmental surfaces such segments being shown integrally connected by a relatively thin web 11. In the illustration the web is shown extending into the neck portion 12 uniting the plug to the handle 7.

Each of the segmental faces l() is shown as having an arc of considerably over 90 degrecs, preferably approximating 120 degrees. Heretofore it has been proposed to form a fiat bar with arc shaped faces for gauging the bore of a hole, but it has been found in practice that a solid cylindrical plug gauge of ordinary construction will not go into a b ore into which the type of gauge just mentioned of the vsame rating will go. In other words such gauges cause a minis error in use. The large contact surface of my improved plug, more nearly approaching a complete cylinder, offers more resistance to deformation than does such flat type of gauge.

When the measuring surfaces of my gauge have become worn, or for some other reasons it is desired to reform the cylindrical surface, the gauge maker strikes the web 1l a blow preferably with the tapering end of a machinlsts hammer while the opposite side of the web is resting upon a suitably formed anvil. This has the effectof expanding the web laterally and carrying the segments 10-10 further apart. The perimeter of the gauge is now out of center and it thereforeI becomes necessary to polish or lap 'the faces of these segments and bring them into-segments having the outline of al true cylinder.

An exaggerated representation in the Fig. 3 diagram shows the web 110 compressed and extended, and the segments 100 moved apart to such an extentthat the axes of their segmental surfaces do not coincide. This lack of concentric-ity of such surfaces is made apparent by the dotted circle 111. The material extending beyond'the cylinJ drical outline which is represented by this circle 111 is lapped off, whereuponthe plug assumes its original or other desired proportions.

If the cylinder becomes somewhat tapered, owing to the wear which naturally takes place at the outer edge, a blow of .a hammer against the end'of the web 11 corrects this error.

The measuring surfaces of the two plug portions 8 and 9 are preferably separated by to my invention both portions, the maxi- Vmal portion and the minimum portion, may

be expanded accordingly by action upon the web l1 throughout lts entire length. ln many instances it is found necessary to justiiy one or the other of these plugs Without altering the other, and in some instances it is found that one or the other will require more alteration for effecting the justification than will the other. rl`he ortion of the web peculiar to the particu ar plug portion which requires treatment may be acted upon independently of the Web portion peculiar to the other plug member so that the justification of one portion may be effected independently, and Without disturbing the set ofthe other plug portion.

The drawings herein are tor the purpose of illustrating the invention, and it is for this reason that some parts are shown out of proportion, since it would be impracticable in a drawing of this character to show the did'erence in diameter between the maximum and minimum plugs which exists in actual practice. Also in the diagram in Fig. 3 it is obvious that the material which is shown extending beyond the proposed contour is far in excess of what will be removed in most instances in practice.

Changes may be made withinthe scope c the claims as occasion requires, without departing .from the spirit ot my invention.

l claim as my invention:

V1. A. reformable gauge, comprising a cy lindrical plug having two diametrically opposite channels formed in its periphery Setting the plug od into two segments Vintegrally connected by a Web, the combined width of said channels being less than ninety degrees at the surface of the cylinder, and the web being capable of elongation by lateral compression.

v 2. A retormable gauge, comprisin a cylindrical plug having two diametrica y opposite channels formed in its periphery setting theplug ofi" into two segments integrally connected by a web, the combined Width of said channels being less than ninety degrees at the surface of the cylinder, and the web being capable of elongation by lateral compression, and a handle integrally 'connected to the web. Y

ln testimony whereof, ll have aliixed :my

signature hereto.

' RBERT F. Rlllhl'lrE. 

